The original idea #134 was OK in 2015. Since then, Java got modular support and java.sql is no longer available by default. This is causing sporadic issues in random places:

• support java.sql.Date and Timestamp types #134 (comment)
• java.lang.ClassNotFoundException: java.sql.Time
• stackoverflow
• gson pom.xml

Would be great to deprecate support for java.sql and suggest writing type adapters instead.